Yet-Ming Chiang co-authored a new paper in Science that offers a stark reminder that there are still huge parts of the global energy system where we simply don’t have affordable ways of halting greenhouse-gas emissions.

Air travel, long-distance transportation and shipping, steel and cement manufacturing, and remaining parts of the power sector account for 27 percent of global emissions from the energy and industrial sectors. And the authors say we need much more research, innovation, and strategic coordination to clean up these sources.